6 best ab workouts for men, according to personal trainers

• Building a strong, defined core requires doing ab-focused exercises as part of a weekly fitness routine.
• Workouts like planks, Russian twists, and cable crunches are effective exercises that anyone can do.
• It's important that each exercise is done with proper form and technique to get the most out of the move.

You don't have to win the genetic lottery to earn a set of strong, defined abs. DNA only determines how many "packs" you have, which are actually just segments of the rectus abdominis muscle. Research has shown that most people have at least three segments or bands (and three bands equal a visible six-pack).

This means that one of the best ways to achieve a defined midsection comes down to how well you take care of your body. In addition to eating nutrient-dense foods, sleeping well, and reducing stress, the type of workouts you do on a regular basis also plays a huge role in working your abs. 

But not all ab workouts are created equal as some are capable of working your core better than others. For help, I spoke to three personal trainers who shared not only what the best ab workouts are but also how to properly do them. 

1. Extended opposite elbow-to-knee crunch

For achieving a midsection burn, certified personal trainer, Morgan Rees, says there are multiple methods for attacking the abs. Her grueling extended opposite elbow-to-knee crunch is one example.

"This crunch hold is one of the most difficult exercises I give my clients," she says. "It allows the spine to go into flexion and into a 'C' curve. You connect your opposite elbow to your knee while lying on your back and holding that position, and allowing your spine to round."

Here's how to do it:

1. Lie on your back with your arms and legs extended.

2. Lift your legs, shoulders, and head off the floor at the same time.

3. Bring your right elbow to your opposite (left) knee, maintaining pressure between them.

4. Hold the position for 30 seconds and then switch sides.

5. Repeat for 3 sets of 10 reps on each side.

2. Plank

The plank is a classic for a reason. Rees says this exercise is great for targeting the entirety of your core and that "isometric moves, such as planks, focus on stabilizing the spine. 

When doing a plank, it's important to keep your core engaged and hold the position for as long as you can. You can also try to increase the duration of the plank as you get stronger.

Here's how to do it:

1. Start in a push-up position with your hands flat on the ground, shoulder-width apart, and directly beneath your shoulders.

2. Engage your core and keep your arms straight.

3. Hold this position for 30 seconds.

4. Rest for 10 seconds and repeat for 3 sets.

3. Russian twists

The Russian twist is an effective move for strengthening the obliques, which are often ignored in many ab workouts. 

"Rotational movements like the Russian twist are a great way to engage both the obliques and internal abdominal muscles," she says.

You can play around with different forms of the move, such as using a medicine ball or dumbbell while you twist.

Here's how to do it:

1. Sit on the floor with your legs bent in front of you and your arms extended in front of your chest.

2. Twist your torso from side to side, keeping tension in your core at all times, and your hips and legs stable.

3. Do 10 reps on each side and repeat for 3 sets.

4. Crunches

No ab workout is complete without crunches. Matt Claes, head coach and founder of Weight Loss Made Practical, recommends both regular and reverse crunches for targeting the abdominals. While standard crunches work the muscle fibers in your upper abs, reverse crunches hit the lower abs.

"You can easily make crunches more challenging by holding something, even just a backpack with some books, against your chest," Claes says, adding that the same is possible for reverse crunches.

Here's how to do standard crunches:

1. Lie on your back with your legs in a tabletop position and hands behind your head.

2. Perform a crunch by bringing your chest up toward your thighs, squeezing at the top of the move.

3. Do 10 reps and repeat for 3 sets.

Here's how to do reverse crunches:

1. Lie flat on your back with your hands at your sides.

2. Raise your legs and bring them up toward your chest, keeping them close together and squeezing at the top of the move.

3. Do 10 reps and repeat for 3 sets.

5. Cable crunch

The cable crunch does require access to a gym and cable machine, but it's an excellent exercise that does well to target the entirety of your core.

"A potential benefit of cable crunches is that some people find lying down on their backs like in regular crunches uncomfortable," Claes says. "Additionally, it's relatively easy to precisely adjust the resistance you use in cable crunches."

Here's how to do it:

1. Attach a rope to the end of a pulley cable and slide the cable to the top of the machine.

2. Sit on your knees in front of the machine, holding the cable against your chest. 

3. Perform the crunch by bringing your elbows toward your knees.

4. Do 10 reps and repeat for 3 sets.

6. Hanging knees to elbows

The dip bar isn't just for pull-ups. Owner of Redefining Strength, Cori Lefkowith, says it's also effective at targeting your ab muscles — especially the lower ones. 

"If you're looking to improve your pull-ups, this is a great supplemental core move to include," she says. "You do need to make sure you round through your spine to curl your knees up and not just flex at your hips to tuck. Spinal rounding is what engages your abs to help you curl as you pull down on the bar."

Here's how to do it:

1. Hang from a set of parallel bars with your hands shoulder-width apart and your feet off the ground.

2. Engage your core and drive your legs up towards your chest and elbows.

3. Lower your legs back down to starting position and repeat for 10 reps.

4. Do 3 sets.

Insider's takeaway

By doing exercises like planks, Russian twists, and cable crunches (if you have access to a gym), you can work on developing a toned and strong core. You can incorporate these into your existing workout routine, or spend a day or two each week focused entirely on abs.

Just remember to always engage your core during each move so you're getting the most out of every rep.